How to unwrap UV for each non-adjacent selected faces?
Assuming your topography won't change from this point forward ( or at least not significantly change ), you can solve this by following these steps:


select the faces you want to unwrap ( in the case the windows ) and detach them by pressing p ( or whatever hotkey you've bound to it ), and selecting "selection"
select the detached object, and go into edit mode
select all faces, press p - select "separate parts"
select all detached objects, and press ctrl+alt+shift+c - origin to center of mass
select one of the windows and unwrap it
select all windows, making sure your unwrapped window is active ( bright orange ) by clicking on it last
press ctrl + l - select "object data"


This will essentially make every window into an instance of the active window. Please note however that this assumes that the geometry of every window is exactly the same.